1. Field of the Invention
This invention relates generally to spacer arrangements, and more particularly, it is directed to spacers for mounting printed circuit boards, discrete components, fans, etc. and method of making the same.
2. Description of the Prior Art
Electronic devices are present in modern equipment from telecommunications to advanced avionics to medical industries. Society has become accustomed to more innovative and sophisticated electronic products, year after year, and advancements in these products have become common place. Such products or devices may have hundreds or even thousands of electrical components mounted on electronic circuit boards. While each circuit board can accommodate a large number of electronic components such as transistors, semiconductor chips, resistors, capacitors, for example, as more functionality is added to electronic assemblies, several circuit boards may be needed to provide the necessary circuitry for the particular electronic product. In such cases, multiple circuit boards are typically mounted together in a stacked arrangement, one board on top of the other. In addition, there is a need to mount accessory items such as descrete devices, cooling fans etc. on a supporting structure within a cabinet.
Conventional spacers, such as the tubular spacer 12 shown in FIG. 1 may be used to structurally separate stacked circuit boards or to mount accessory items on a supporting surface. The conventional spacer 12 has a cylindrical shaped body with a bore 14 therethrough and is typically made from a hard plastic material, such as nylon. It comes in a variety of heights to provide the desired amount of board separation. Conventional spacers also readily slide on and off the shaft of a screw. While conventional spacers provide good structural separation support, they are not assembler friendly, as they easily slide off the screw they have been mated with, prior to or during the assembly process. Production time is therefore wasted and the cost of assembling an electronic product increases. When hundreds or thousands of products are being assembled, the increased production can be significant. With the ever-present pressure to drive costs down in order to be competitive in the consumer electronic market other spacers have evolved.
One such spacer is illustrated in FIG. 2, in which a screw spacer 16 includes a ribbed inner wall 18. A screw inserted into the spacer is held therein by the ribs. However, in order to provide the spacer with sufficient rigidity to provide the necessary mechanical separation support, this spacer 16 as with the conventional spacer described above, must be made of hard plastic material. Accordingly, while spacer 16 provides an improvement over the above-described conventional spacers, screws with a wide range of thread diameter tolerances may either be difficult to insert into spacer 16 or slip out of the spacer altogether. As such, there is still a need for a versatile spacer that provides a dependable solution for quick mechanical assembly and reduced assembly time that is simple to manufacture in large quantities. Additionally, it may be desirable to have a spacer arrangement that accommodates a variety of screws with different thread sizes.